1. Field of the Invention
The present invention is generally directed to display techniques. More particularly, the present invention is directed to 3D display techniques and applications thereof.
2. Background
Frame-sequential stereoscopic display technology enables images to be displayed in 3D. In frame-sequential stereoscopic display, an alternating sequence of left- and right-perspective images are displayed, wherein the left-perspective images are intended to be viewed by a user's left eye and the right-perspective images are intended to be viewed by the user's right eye. If the left- and right-perspective images are successively displayed at an appropriate rate (e.g., approximately 60 Hz/perspective), the user will perceive the images as being in 3D.
Frame-sequential stereoscopic images may be provided on a display (e.g., a television or other display device) that is coupled to a device (e.g., a computer or a video-game console) having a processing unit (e.g., a central-processing unit (CPU) and/or a graphics-processing unit (GPU)). In this way, the frame-sequential stereoscopic display enables a user to, for example, watch movies and/or play video games in 3D.
Unfortunately, the quality of the frame-sequential stereoscopic display may be limited by the response time of the display. For example, if a display does not have a sufficiently high response time (which is a fairly common problem for liquid crystal displays (LCDs) in particular), then when the display is driven for frame-sequential stereoscopic 3D residual information intended for the left eye may be present in the right-perspective image and vice-versa. The residual information may appear as one or more faint ghost images. These faint ghost images may appear to the left and right of the intended image depending on the depth of the object in the 3D scene.
One potential solution for reducing the appearance of such undesirable residual images is to use 3D technologies other than frame-sequential stereoscopic display. But these other 3D technologies typically lower the perceived resolution of the images and, therefore, are undesirable.
Another potential solution for reducing the appearance of these undesirable residual images is to use techniques designed to increase the response time of a standard LCD display, such as black frame insertion. In black frame-insertion techniques, the total brightness is limited by reducing the “on time” of the pixels in the panel. But one problem with this potential solution is that the black frame-insertion techniques are designed to minimize the response time that is measured and published as a specification of the display, but these techniques are not designed to reduce residual images caused by frame-sequential stereoscopic display. Consequently, it is not clear that black frame-insertion techniques would actually work to reduce the appearance of residual images that may occur in frame-sequential stereoscopic display.
An additional potential solution for reducing the appearance of these undesirable residual images is to adjust the shuttering mechanism to mask the appearance of any residual images. But this solution is undesirable because it would cause a reduction in the perceived brightness.
Given the foregoing, what is needed are methods, apparatuses, and systems for reducing the appearance of residual images that may occur in frame-sequential stereoscopic-3D displays.